JP2002312918A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording medium combined with a vertical magnetization film, in which an in-plane magnetization layer for reducing a noise and preventing the distortion of a reproducing waveform, is used as a recording layer. SOLUTION: The magnetic recording medium includes a recording in-plane magnetization film having a easily magnetizable axis in an in-plane direction, and a vertical magnetization film formed on the in-plane magnetization film, whose easily magnetizable axis is oriented in the vertical direction with respect to the easily magnetizable axis of the in-plane magnetization film, and tBr of the vertical magnetization film is set not to exceed 1/5 of tBr of the in-plane magnetization film even at the maximum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium used in a magnetic recording / reproducing apparatus employed as an external recording device for an information processing apparatus such as a computer.

[0002]

2. Description of the Related Art Many studies have been made on the use of a combination of a perpendicular magnetization film and an in-plane magnetization film for a recording layer of a magnetic recording medium such as a hard disk.
For example, Japanese Patent Application Laid-Open No. H11-283229 discloses a recording method in which a perpendicular magnetic film is formed thick and recording is performed on the perpendicular magnetic film using a magnetic head for in-plane recording. This recording method has an advantage that no waveform processing is required since an in-plane recording type reproduction waveform can be obtained even though the recording is performed on the perpendicular magnetization film.

[0003] For example, Japanese Patent Application Laid-Open No. 5-189737 discloses that two types of hard magnetic layers in which a magnetization reversal mode is a domain wall displacement type and a magnetization rotation type at a transition position (magnetization reversal position) in a recording state, respectively. A method of combining an alignment film (a perpendicular magnetization film and an in-plane magnetization film) is disclosed. It is said that this method can improve the overwrite characteristics and increase the S / N ratio.

[0004]

In a composite magnetic recording medium in which a perpendicular magnetic film and an in-plane magnetic film are combined as described above, many proposals have been made regarding recording on the perpendicular magnetic film. However, the magnetic recording medium is not yet satisfactory at a practical level.

Recently, as described above, a composite recording medium using a perpendicular magnetization film and an in-plane magnetization film as described above, but the in-plane magnetization film is used as a recording layer, and the perpendicular magnetization film is used as the in-plane magnetization film. There is a proposal to use it as an auxiliary film for enhancing the function of the above. Such a magnetic recording medium has a structure in which a perpendicular magnetization film is combined with an in-plane magnetization film to form a horseshoe-shaped magnetization mode so that a magnetic field from the in-plane magnetization film is returned. It has been pointed out that a configuration capable of achieving an increase and a reduction in noise can be achieved and a high recording density can be achieved.

However, in the case of the composite recording medium having the above-mentioned in-plane magnetic film as a recording layer, there is a problem of noise generation due to a demagnetizing field at a transition position of the in-plane magnetic film and a combination of the in-plane magnetic film and a perpendicular magnetic film. There is a problem of distortion of the reproduced waveform due to the structure. However, there has not yet been proposed a composite recording medium having a recording layer formed of an in-plane magnetic film having a preferable configuration and solving such a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite recording medium with a perpendicular magnetic film having an in-plane magnetic film as a recording layer for reducing noise and preventing distortion of a reproduced waveform.

[0008]

According to a first aspect of the present invention, there is provided an in-plane magnetic film for recording having an easy axis of magnetization in an in-plane direction, and a magnetic film formed on the in-plane magnetic film. A perpendicular magnetization film whose easy axis is oriented in a direction perpendicular to the easy axis of magnetization of the in-plane magnetization film, wherein the perpendicular magnetization film has a maximum tBr of at least the in-plane magnetization film. Is achieved by a magnetic recording medium which is set so as not to exceed 1/5 of tBr.

According to the first aspect of the present invention, since the magnetization state of the perpendicular magnetization film is limited to a predetermined range, the perpendicular magnetization film sufficiently fulfills the function of assisting the in-plane magnetization film serving as the recording layer. Thus, a composite magnetic recording medium that suppresses distortion of a reproduced waveform and obtains a high S / N is obtained.

The tBr of the perpendicular magnetization film may be set to be at most 1/5 of the tBr of the in-plane magnetization film, but more preferably 1/10 of the tBr of the in-plane magnetization film.
Set up to.

According to a second aspect of the present invention, in the magnetic recording medium according to the first aspect, it is preferable that the perpendicular magnetization film has a maximum thickness not exceeding 5 nm.

According to the second aspect of the invention, it is possible to more reliably suppress the distortion of the reproduction waveform of the magnetic recording medium.

According to a third aspect of the present invention, in the magnetic recording medium according to the first or second aspect, the anisotropic magnetic field Hk of the perpendicular magnetization film is the same as that of the in-plane magnetization film. It is desirable to adopt a configuration that is set to at least 1.2 times Hk.

According to the third aspect of the present invention, the transition position of the perpendicular magnetization film can be surely matched with the transition position of the in-plane magnetization film, and the demagnetizing field which is easily generated at the transition position of the in-plane magnetization film And noise can be reduced.

According to a fourth aspect of the present invention, in the magnetic recording medium according to any one of the first to third aspects, a configuration is employed in which a nonmagnetic spacer is provided between the in-plane magnetic film and the perpendicular magnetic film. It is desirable to do.

According to the fourth aspect of the present invention, the perpendicular magnetization film can be easily formed on the in-plane magnetization film. As the non-magnetic spacer, it is preferable to use a material on which the crystallinity of the perpendicular magnetization film is improved.
An oCr-based alloy or the like can be employed.

According to a fifth aspect of the present invention, in the magnetic recording medium according to the fourth aspect, the non-magnetic spacer includes
It is desirable to have a structure having a film thickness not exceeding nm.

According to the fifth aspect of the present invention, it is possible to maintain a good distance between the magnetic head for recording / reproducing and the in-plane magnetic film serving as the recording layer.

According to a sixth aspect of the present invention, in the magnetic recording medium according to any one of the first to fifth aspects, the perpendicular magnetization film is formed of a Co-based alloy or a Co-based artificial lattice film. Is also good.

As the perpendicular magnetization film, a general magnetic material such as a CoCr-based alloy can be used. However, from the viewpoint of preferably having a high anisotropic magnetic field, a Co-based alloy or a Co-based alloy is preferable.
It is recommended to use a system artificial lattice membrane.

As the Co-based alloy, for example, CoCrP
t, TbFeCo, CoPt, FePt, etc. can be used.
o / Pt, Co / Pd or the like can be used.

Further, the scope of the present invention includes a magnetic recording / reproducing apparatus including the magnetic recording medium according to any one of claims 1 to 6, as described in claim 7. Such a magnetic recording / reproducing apparatus can record information with high density and high sensitivity since it has low noise and a good reproduction waveform.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

The composite type magnetic recording medium of this embodiment (hereinafter referred to as
A perpendicular / in-plane composite medium) is formed on a substrate (not shown) on an in-plane magnetization film having an easy-axis in the in-plane direction, and on the in-plane magnetization film, the easy-axis is set with respect to the substrate. And a perpendicular magnetization film oriented in the vertical direction. The perpendicular / in-plane composite medium preferably has a configuration in which a non-magnetic spacer is inserted between the in-plane magnetization film and the perpendicular magnetization film. Therefore, in the present embodiment, a perpendicular / in-plane composite medium having a laminated structure of an in-plane magnetic film, a non-magnetic spacer, and a perpendicular magnetic film will be described as an example.

In the present perpendicular / in-plane composite medium, the in-plane magnetic film serves as a recording layer, and the perpendicular magnetic film thereon functions as an auxiliary film.

The in-plane magnetized film is made of, for example, CoCrP.
Magnetic materials such as t and CoCrPtB can be used. In addition, for example, a Co-based alloy, Co
It is preferable to use a magnetic material such as a system artificial lattice film.

The thickness of the in-plane magnetized film is, for example, 5 to 20.
The thickness of the perpendicular magnetization film can be set to about 1 to 5 nm. In particular, the thickness of the perpendicular magnetization film is at most 5n.
It is preferably up to about m.

In the present embodiment, in order to facilitate understanding, a single-layer in-plane magnetized film having an easy axis of magnetization in a general in-plane direction is used for the perpendicular / in-plane composite medium of this embodiment. The case of the magnetic recording medium (hereinafter, referred to as an in-plane single-layer medium) provided as described above will be described as a comparative example.

FIG. 1 is a diagram showing the relationship between a longitudinal recording type magnetic head 10 and a magnetic recording medium. FIG. 1 shows a magnetic head 1 of an in-plane recording type in which a magnetic spacing 11 is matched.
0 indicates that recording is performed on the perpendicular / in-plane composite medium 20 and the in-plane single-layer medium 30 of this embodiment.
In the perpendicular / in-plane composite medium 20 of this embodiment, magnetic information is recorded or reproduced by the magnetic head 10 as described above.

The perpendicular / in-plane composite medium 20 has a structure in which the in-plane magnetic film 21, the non-magnetic spacer 22, and the perpendicular magnetic film 23 are laminated as described above.

The prerequisites defined for the perpendicular / in-plane composite medium 20 and the in-plane single-layer medium 30 are as follows. The parameter he of the exchange interaction between magnetic particles in the films of the perpendicular / in-plane composite medium 20 and the in-plane single layer medium 30 was set to 0.05. The transition width and the S / N ratio were calculated by recording dibits at each recording density. The transition width was estimated by approximating the in-plane residual magnetization component with an arctangent function. However, in the transition width of the composite medium, the in-plane magnetization component of the perpendicular film is also added at the ratio of the film thickness. However, since the tBr of the perpendicular magnetization film is low, there is no effect on the effect of reducing the transition width. Have confirmed.
The noise in the S / N ratio was determined by integrating the fluctuation components of the reproduction output.

[Embodiment 1] FIG. 2 is a vertical sectional view of Embodiment 1 of the present invention.
The structure of the in-plane composite medium 20 is changed to the in-plane single-layer medium 30 of the comparative example.
It is the figure collectively shown with the structure of FIG.

As shown in FIG. 2, the structure of the perpendicular / in-plane composite medium 20 of the present embodiment is such that an in-plane magnetic film 10 nm, a non-magnetic spacer 1 nm, and a perpendicular magnetic film 1 nm are sequentially stacked from the bottom. . On the other hand, the in-plane single-layer medium 30 of the comparative example is formed of a single layer having only the in-plane magnetic film of 10 nm. The magnetic particle diameter of each film is adjusted to 5 nm, and the parameter he of the exchange interaction between the magnetic particles is set to 0.05.

The magnetic head 10 capable of recording and reproduction shown in FIG. 1 has a magnetic spacing of 24 nm, a write head magnetic field of 2 kOe (at the center of a medium having a thickness of 10 nm),
Write gap length 0.2 μm, read gap length 0.0
It was adjusted to 9 μm.

FIG. 3 shows a perpendicular / in-plane composite medium 2 of this embodiment.
FIG. 2 is a diagram collectively showing magnetic characteristics when recording and reproducing are performed on a 0 and an in-plane single layer medium 30 by a magnetic head 10.

The perpendicular / in-plane composite medium 20 is
The anisotropic magnetic field Hk of the perpendicular magnetization film is set to 8 kOe and the saturation magnetization M
Two types were prepared in which s was changed to 250 emu / cc and 500 emu / cc, and tBr was set to 3.1 Gm and 6.3 Gm.

As shown in FIG. 3, tBr4 of the in-plane magnetized film
For 7.1 G μm, the saturation magnetization Ms of the perpendicular magnetization film is 2
50, 500 emu / cc (tBr 3.1, 6.3 Gμ
For each of the cases of m), changes with respect to the in-plane single-layer medium 30 were compared. The recording density was 200 kfci.
And

The output V (single film ratio: ratio to the in-plane single layer medium 30) and the transition width πa (single film ratio) are shown in the two columns on the right end side of FIG. In these columns, the output V (single film ratio) and the output V (single film ratio) for the two types of perpendicular / in-plane composite media 20 are set based on 0 (%) based on the case of the in-plane single-layer medium 30 formed only of the in-plane magnetic film. The change in the transition width πa (the ratio of the single film) is shown in percentage.

As the magnetic recording medium, it is better to obtain a large output V, and from the viewpoint of noise reduction, the smaller the transition width πa is, the better.

Here, tBr of the perpendicular magnetization film is 6.3 Gμ.
When m is high, it can be confirmed that the output is significantly reduced as compared with a low case where tBr is 3.1 G μm. Conversely, it can be confirmed that the transition width increases when tBr is high.

Therefore, it is understood that it is necessary to suppress tBr of the perpendicular magnetization film to be low.

The present inventors have determined that the tBr of the perpendicular magnetization film
It has been confirmed that it is preferable to set the value so as not to exceed 1/5 of tBr of the in-plane magnetized film. More preferably, tBr of the perpendicular magnetization film is set so as not to exceed 1/10 of tBr of the in-plane magnetization film.

That is, when tBr of the perpendicular magnetization film increases, the transition width increases due to magnetostatic interaction with the in-plane magnetization film. Therefore, it is important to appropriately suppress the magnetostatic interaction. For this purpose, it is effective to reduce the tBr of the perpendicular magnetization film and to insert a nonmagnetic spacer of about 1 nm. The thickness of the non-magnetic spacer affects the magnetic spacing with the magnetic head.
It is preferably up to about nm. From the same viewpoint, it is preferable to design the thickness of the perpendicular magnetization film so as not to exceed 5 nm.

[Embodiment 2] FIG. 4 is a diagram showing the structure of a perpendicular / in-plane composite medium 20 of Example 2 together with the structure of an in-plane single-layer medium 30 of a comparative example.

As shown in FIG. 4, in the perpendicular / in-plane composite medium 20 of this embodiment, the thickness of the in-plane magnetization film is set to be 6 nm smaller than that of the medium of the first embodiment shown in FIG. The other configuration is the same as that of the first embodiment except that the nonmagnetic spacer is 1 nm and the perpendicular magnetization film is 1 nm.

In the present embodiment, the in-plane single-layer medium 30 of the comparative example is
It is formed of a single layer of only the in-plane magnetized film of 6 nm. The magnetic particle diameter of each film was adjusted to 5 nm as in the case of FIG.
The parameter he of the exchange interaction between the magnetic particles is also 0.05.
It is.

The condition of the magnetic head 10 shown in FIG. 1 is changed. That is, the magnetic spacing of the magnetic head 10 is 17 nm, the write head magnetic field is 7.5 kOe (at the center of the medium having a thickness of 6 nm), and the write gap length is 0.
The length was 15 μm and the read gap length was 0.05 μm.

FIG. 5 shows a vertical / in-plane composite medium 2 of this embodiment.
FIG. 2 is a diagram collectively showing magnetic characteristics when recording and reproducing are performed on a 0 and an in-plane single layer medium 30 by a magnetic head 10.

As shown in FIG. 5, tBr5 of the in-plane magnetized film
For 6.5 Gμm, the saturation magnetization Ms of the perpendicular magnetization film is set to 6
00, 200 emu / cc (tBr 7.5, tBr2.
A plurality of perpendicular / in-plane composite media 20 having a thickness of 5 Gm was prepared.

Here, the medium as the perpendicular / in-plane composite medium 20 is one in which the transition positions of the perpendicular magnetization film and the in-plane magnetization film are matched. The medium as the perpendicular / in-plane composite medium 20 is one in which the transition positions of the perpendicular magnetization film and the in-plane magnetization film are not matched.

In this embodiment, the influence on the reproduction (output) waveform and S / N was confirmed by determining whether or not the transition positions of the perpendicular magnetization film and the in-plane magnetization film were made to coincide with each other.

In the second embodiment, as shown in FIG.
Four types of in-plane composite media were prepared. Denotes an in-plane single-layer medium 30 of a comparative example.

The transition position of the in-plane magnetic film in each of the four types was adjusted by the anisotropic magnetic field Hk of the perpendicular magnetic film.

In FIG. 5, the composite medium is a case where the transition positions are matched. The transition position of the composite medium is shifted by one magnetic particle (about 5 nm), and the transition position of the composite medium is shifted by 4 magnetic particles (about 21 nm).

In order to suppress the deviation of the transition position of the perpendicular magnetization film from the transition position of the in-plane magnetization film, the inventors of the present application require that the anisotropy magnetic field Hk of the perpendicular magnetization film be at least anisotropy of the in-plane magnetization film. It has been confirmed that 1.2 times or more of the magnetic field is required. Therefore, the intensity of the anisotropic magnetic field Hk of the perpendicular magnetization film can be adjusted so that the transition position of the perpendicular magnetization film coincides with the transition position of the in-plane magnetization film. In the second embodiment, the recording density was 460 kfci.

As shown in FIG. 5, in the composite medium in which the transition position of the perpendicular magnetization film coincides with the transition position of the in-plane magnetization film, the output is 6.3% as compared with the in-plane single-layer medium 30 of the comparative example. Although decreasing, the S / N is improved by 15.1. The single-layer ratio (dB) in the rightmost column in FIG. 5 can be regarded as a comprehensive evaluation of the in-plane single-layer medium 30 of the comparative example. As a result, +1.2 dB is obtained from the in-plane single-layer medium 30.

Further, in the composite medium in which the transition positions coincide, the tBr of the perpendicular magnetization film is further increased by the tBr of the in-plane magnetization film.
If it is set to be 1/5 of Br, a high S / N ratio can be obtained.

The tBr of the medium is 2.5, and the tBr of the in-plane magnetized film is
Since Br is 56.5, (2.5 / 56.5) ≦
(1/5) is satisfied. The medium has a tBr of 7.5.
And satisfies (7.5 / 56.5) ≦ (1/5).

Therefore, in the case of the medium, a result of +0.9 is finally obtained from the in-plane single-layer medium 30. However, in order to obtain a higher S / N ratio like a medium, it is necessary to design so that tBr of the perpendicular magnetization film does not exceed 1/10 of tBr of the in-plane magnetization film.

Also, the composite medium of FIG. 5 is designed so that tBr of the perpendicular magnetization film does not exceed 1/10 of tBr of the in-plane magnetization film. Although good evaluation has been obtained, high evaluation cannot be obtained like the medium.

In order to obtain a more preferable perpendicular / in-plane composite medium 20, the tBr of the perpendicular magnetization film is limited to a predetermined value lower than the tBr of the in-plane magnetization film, and the transition position of the perpendicular magnetization film is set in the in-plane. It is desirable that the magnetic film be formed so as to coincide with the transition position. Matching transition positions in this way,
It is presumed that the magnetization of the perpendicular magnetization film functions so as to return the magnetic field at the transition position of the in-plane magnetization film. This allows
The demagnetizing field at the transition position of the in-plane magnetization film can be reduced.

As shown in the column of the anisotropic magnetic field Hk in FIG. 5, in the case of the composite medium, the anisotropic magnetic field Hk of the perpendicular magnetization film is one of the anisotropy magnetic field Hk of the in-plane magnetization film. .2 times or more.

FIG. 6 is a diagram showing a reproduction waveform of a composite medium in comparison with a reproduction waveform of an in-plane single-layer medium. FIG. 6A shows a comparison with a medium, and FIG. 6B shows a comparison with a medium.

The medium having a lower tBr of the perpendicular magnetization film shown in FIG. 6B has a smaller tBr of the perpendicular magnetization film shown in FIG.
It can be confirmed that the distortion of the reproduction waveform in the composite medium due to the presence of the perpendicular magnetization film is suppressed as compared with the medium having a high magnetic field.

Further, in the composite medium of this embodiment, even when the magnetic field of the recording head is changed, the transition position can be adjusted as shown in FIG. 7, and as shown in FIG. / N, and the transition width can be reduced as shown in FIG.

In the perpendicular / in-plane composite medium described above, a high S / N ratio can be obtained by suppressing the distortion of the reproduced waveform while suppressing the generation of noise by combining the perpendicular magnetization film and the in-plane magnetization film. It can be provided as a high recording density magnetic recording medium.

For the perpendicular / in-plane composite medium of the above embodiment, the Landau-Lifshitz-Gilbert equation was used.
Similar results can be obtained by simulation using a micromagnetic model. At this time, the magnetic field generated by the magnetic head can be determined by an analysis formula by Kalquvist assuming a ring head, and the reciprocity theorem can be used for reproduction output.

Next, an embodiment of the magnetic recording / reproducing apparatus according to the present invention will be described with reference to FIGS. FIG. 9 is a sectional view showing a main part of an embodiment of a magnetic recording / reproducing apparatus, and FIG. 10 is a plan view showing a main part of the apparatus.

As shown in FIGS. 9 and 10, the magnetic recording / reproducing apparatus generally comprises a housing 113. Housing 1
Inside 13, a motor 114, a hub 115, a plurality of magnetic recording media 116, a plurality of recording / reproducing heads 117, a plurality of suspensions 118, a plurality of arms 119, and an actuator unit 120 are provided. The magnetic recording medium 116 is attached to a hub 115 rotated by a motor 114. The recording / reproducing head 117 is a composite recording / reproducing head including a reproducing head such as an MR head and a GMR head and a recording head such as an inductive head. Each recording / reproducing head 117 has a corresponding arm 119.
Is mounted via a suspension 118 at the tip of the. The arm 119 is driven by the actuator unit 120. The basic configuration itself of this magnetic recording / reproducing apparatus is well known, and a detailed description thereof will be omitted in this specification.

The embodiment of the magnetic recording / reproducing apparatus is characterized by a magnetic recording medium 116. Each magnetic recording medium 116 has, for example, the configuration of the composite medium described with reference to FIG. Of course,
The number of magnetic recording media 116 is not limited to three, but may be one, two, or four or more.

The basic configuration of the present magnetic recording / reproducing apparatus is not limited to those shown in FIGS. Also,
The magnetic recording medium used in the present invention is not limited to a magnetic disk.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the specific embodiments, and various modifications may be made within the scope of the present invention described in the appended claims. Can be modified and changed.

[0073]

As is apparent from the above description, according to the first aspect of the present invention, since the magnetization state of the perpendicular magnetization film is limited to a predetermined range, the perpendicular magnetization film becomes the recording layer. It is possible to form a composite magnetic recording medium that sufficiently fulfills the function of assisting the in-plane magnetic film, suppresses distortion of the reproduced waveform, and obtains a high S / N.

According to the second aspect of the present invention, it is possible to more reliably suppress the distortion of the reproduction waveform of the magnetic recording medium.

According to the third aspect of the present invention, the transition position of the perpendicular magnetization film can be surely matched with the transition position of the in-plane magnetization film, so that the transition position of the in-plane magnetization film easily occurs. Noise can be reduced by suppressing the demagnetizing field.

According to the fourth aspect of the present invention, a perpendicular magnetization film can be easily formed on an in-plane magnetization film.

According to the fifth aspect of the present invention, it is possible to maintain a good distance between the magnetic head for recording and reproducing and the in-plane magnetic film serving as the recording layer.

According to the invention described in claim 6, a magnetic recording medium having a more preferable perpendicular magnetization film is obtained.

According to the seventh aspect of the present invention, a magnetic recording / reproducing apparatus capable of high-density and high-sensitivity information recording can be provided because of low noise and good reproduction waveform.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a longitudinal recording type magnetic head and a magnetic recording medium.

FIG. 2 is a diagram collectively showing a configuration of a perpendicular / in-plane composite medium of Example 1 together with a configuration of an in-plane single-layer medium of a comparative example.

FIG. 3 is a diagram collectively showing magnetic characteristics when recording / reproducing is performed on a perpendicular / in-plane composite medium and an in-plane single-layer medium by a magnetic head in Example 1.

FIG. 4 is a diagram collectively showing a configuration of a perpendicular / in-plane composite medium of Example 2 together with a configuration of an in-plane single-layer medium of a comparative example.

FIG. 5 is a diagram collectively showing magnetic characteristics when recording / reproducing is performed by a magnetic head on a perpendicular / in-plane composite medium and an in-plane single-layer medium of Example 2.

FIG. 6 is a diagram showing the reproduction waveforms of the perpendicular / in-plane composite medium and the respective reproduction waveforms of the in-plane single-layer medium.

FIG. 7 is a diagram illustrating conditions when a magnetic field of a recording head is changed.

FIG. 8 is a diagram illustrating the magnetic field, S / N, and transition width of a recording head.

FIG. 9 is a sectional view showing a main part of one embodiment of the magnetic recording / reproducing apparatus.

FIG. 10 is a plan view showing a main part of one embodiment of a magnetic recording / reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic head 11 Magnetic spacing 20 Perpendicular / in-plane composite medium 21 In-plane magnetization film 22 Non-magnetic spacer 23 Perpendicular magnetization film 30 In-plane single layer medium

[Procedure amendment]

[Submission date] August 15, 2001 (2001.8.1
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0067

[Correction method] Change

[Correction contents]

Note that the perpendicular / in-plane composite medium of the above embodiment is obtained by using the Landau-Lifshitz-Gilbert equation.
Similar results can be obtained by simulation using an icromagnetic model. At this time, the magnetic field generated by the magnetic head can be determined by Karlqvist, which assumes a ring head, and the reciprocity theorem can be used for reproduction output.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuya Whirlpool 4-1, 1-1 Kamidadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Atsushi Tanaka 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. 1 Fujitsu Limited F term (reference) 5D006 BB01 BB08 CA05 DA03 DA08 FA09

Claims (7)

[Claims] An in-plane magnetic film for recording having an easy axis in an in-plane direction; and an easy axis formed on the in-plane magnetic film, wherein the easy axis is relative to the easy axis of the in-plane magnetic film. A perpendicular magnetization film oriented in a vertical direction, wherein the perpendicular magnetization film has a maximum tBr of at least t of the in-plane magnetization film.
A magnetic recording medium set so as not to exceed 1/5 of Br. 2. The magnetic recording medium according to claim 1, wherein the perpendicular magnetization film has a thickness not exceeding 5 nm at maximum. 3. The magnetic recording medium according to claim 1, wherein the anisotropic magnetic field Hk of the perpendicular magnetization film is set to at least 1.2 times the anisotropic magnetic field Hk of the in-plane magnetization film. A magnetic recording medium, comprising: 4. The magnetic recording medium according to claim 1, wherein a non-magnetic spacer is provided between the in-plane magnetic film and the perpendicular magnetic film. 5. The magnetic recording medium according to claim 4, wherein said non-magnetic spacer has a thickness not exceeding 2 nm. 6. The magnetic recording medium according to claim 1, wherein the perpendicular magnetization film is formed of a Co-based alloy or a Co-based artificial lattice film. 7. A magnetic recording / reproducing apparatus including the magnetic recording medium according to claim 1.